Post columnist Matt Miller has joined Tom Friedman and others in calling for a third-party, or independent, candidate for president, a radical centrist to take over American politics, shake it by the lapels and blow up the political order and its awful two-party system. Their model is Americans Elect, an impressive organization created by policy and business entrepreneur Peter Ackerman that is using the Web to gain millions of adherents for an Internet convention to nominate a third presidential candidate; the group is moving rapidly to get on state ballots for 2012.

When it comes to dismay over contemporary political dysfunction, we yield to no one. But the call for a third way, in this case, is misguided.

A strong independent candidacy from the center could have several outcomes. Imagine the most improbable — election as president. Winning the White House requires winning a majority of the 538 electoral votes. In a general election with three credible candidates, the ability of any one to collect 270 is limited — and the ability of a third candidate to prevail means running the table on a series of firmly blue and red states. A third candidate would most likely have to find another way — namely, to win a sufficient plurality of electoral votes, combined with a plurality of popular votes.

If no candidate gets a majority in the Electoral College, the House decides the outcome among the top three vote-getters, voting by state. In other words, a third candidate would have to prevail in a House where all but a handful of representatives are Democrats or Republicans, and where small delegations with strong partisan leanings — think Wyoming, South Dakota, Delaware and Hawaii — are the least likely to vote for a third candidate.

Even if an independent did prevail, how would he or she govern? Few in the House or Senate would feel allegiance to or affinity for the newly elected president. Nothing in the movement for an independent presidential candidate is affecting recruitment of House and Senate candidates. That recruitment is already far along for 2012 and, combined with the redistricting process, is moving us toward more, not less, polarization in Congress. It is tough enough for a president to deal with Congress when about half of its members share a party allegiance with the executive. An independent with no partners appealing to a nonexistent congressional center? Fuhgeddaboudit.

Far more likely is that an independent or third-party candidate, whether an ideological one such as George Wallace or a non-ideologue such as John Anderson or Ross Perot, would fall short. But consider three ways a third candidate can affect the outcome of a presidential contest.

First, a third candidate can end up tilting the contest toward another candidate. In 2012, the nightmare scenario for us would be angry or demoralized independents and discouraged centrist Republicans gravitating toward the third candidate, enabling a far-right Republican nominee to prevail with a narrow electoral majority or with a plurality followed by a win in a deeply divided House. (Americans Elect, to its credit, has tried to draft electoral rules so that, in the plurality scenario, its electors would pledge to vote for the most centrist or reasonable major-party nominee.)

Second, one of the major-party nominees could win a clear electoral victory, albeit with diminished popular support because of the three-way contest. The reduced popular support would undercut the legitimacy of the result and curtail momentum for the victor. In this tough environment, any diminishment of legitimacy for the winner is undesirable.

The only positive scenario is that the third candidate speaks tough truths to Americans and, like Perot in 1992, changes the dialogue and the dynamic in positive ways. Miller and Friedman could both name issues, such as a major increase in the gasoline tax, where President Obama, like his predecessors and opponents, have feared to tread. But most other tough truths about deficits and debt — Miller’s commendable obsession — have been told repeatedly by figures such as Alan Simpson, Alice Rivlin, Mark Warner and Warren Buffett, with little effect on public opinion. (If pressed, Miller and Friedman would probably acknowledge that Obama favors most of the policies they espouse. Their real problem is with the politics of obstruction pursued by congressional Republicans, from the use of the Senate filibuster to hostage-taking over the budget and the debt limit.)

Of course, a candidate in a presidential campaign can have an outsize impact. But whether a candidate would take on not just those issues but bigger ones — such as bold action in a faltering economy, how to deal with immigration, and how to shape America’s role in an uncertain world — is not at all clear, especially since we don’t know who that third-party candidate would be.

We share Miller and Friedman’s goal of setting better long-term policies to meet the challenges before our nation. And the spirit in which they make their call is commendable. But the vehicle they suggest is wrong.

Norman J. Ornstein is a resident scholar at the American Enterprise Institute. Thomas E. Mann is a senior fellow at the Brookings Institution.

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